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Subject[PATCH] uio: Support 36-bit physical addresses on 32-bit systems
Date
From: Kai Jiang <Kai.Jiang@freescale.com>

To support >32-bit physical addresses for UIO_MEM_PHYS type we need to
extend the width of 'addr' in struct uio_mem. Numerous platforms like
embedded PPC, ARM, and X86 have support for systems with larger physical
address than logical.

Since 'addr' may contain a physical, logical, or virtual address the
easiest solution is to just change the type to 'unsigned long long'
regardless of which type is utilized.

For physical address we can support up to a 44-bit physical address on a
typical 32-bit system as we utilize remap_pfn_range() for the mapping of
the memory region and pfn's are represnted by shifting the address by
the page size (typically 4k).

Signed-off-by: Kai Jiang <Kai.Jiang@freescale.com>
Signed-off-by: Minghuan Lian <Minghuan.Lian@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
---
drivers/uio/uio.c | 8 ++++----
include/linux/uio_driver.h | 2 +-
2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c
index d2efe82..a927c51 100644
--- a/drivers/uio/uio.c
+++ b/drivers/uio/uio.c
@@ -69,7 +69,7 @@ static ssize_t map_name_show(struct uio_mem *mem, char *buf)

static ssize_t map_addr_show(struct uio_mem *mem, char *buf)
{
- return sprintf(buf, "0x%lx\n", mem->addr);
+ return sprintf(buf, "0x%llx\n", mem->addr);
}

static ssize_t map_size_show(struct uio_mem *mem, char *buf)
@@ -79,7 +79,7 @@ static ssize_t map_size_show(struct uio_mem *mem, char *buf)

static ssize_t map_offset_show(struct uio_mem *mem, char *buf)
{
- return sprintf(buf, "0x%lx\n", mem->addr & ~PAGE_MASK);
+ return sprintf(buf, "0x%llx\n", mem->addr & ~PAGE_MASK);
}

struct map_sysfs_entry {
@@ -634,8 +634,8 @@ static int uio_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL)
page = virt_to_page(idev->info->mem[mi].addr + offset);
else
- page = vmalloc_to_page((void *)idev->info->mem[mi].addr
- + offset);
+ page = vmalloc_to_page((void *)(unsigned long)
+ idev->info->mem[mi].addr + offset);
get_page(page);
vmf->page = page;
return 0;
diff --git a/include/linux/uio_driver.h b/include/linux/uio_driver.h
index 665517c..c1fdb19 100644
--- a/include/linux/uio_driver.h
+++ b/include/linux/uio_driver.h
@@ -31,7 +31,7 @@ struct uio_map;
*/
struct uio_mem {
const char *name;
- unsigned long addr;
+ unsigned long long addr;
unsigned long size;
int memtype;
void __iomem *internal_addr;
--
1.7.3.4


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